Scientists use simulator to prove coral resilience

JERUSALEM — Amid summer heat waves, flocks of snorkelers seek coolness and colorful corals in the southernmost Israeli city of Eilat, a popular Red Sea resort.

Meanwhile, on the shore, some eye-catching corals placed in water tanks are also basking in the sun, but not for exhibition. It is for scientific experiments against the backdrop of growing global climate challenges.

"Here we are at the Red Sea simulator where experiments simulating future conditions in the Red Sea are run," Maoz Fine, head of the Laboratory for Coral Reef Ecology at the Interuniversity Institute for Marine Sciences in Eilat, said ahead of World Environment Day, which was on Monday.

"The reason why we aim to predict future conditions is mainly because coral reefs are suffering and dying throughout the world."

Covering only 0.2 percent of the ocean floor, coral reefs are home to at least a quarter of all marine animals and plants. A special report on the impact of global warming released by the Intergovernmental Panel on Climate Change found that coral reefs were likely to decline between 70 and 90 percent if the temperature increased by 1.5 C.

Located at nearly 29 degrees north latitude, the northern end of the Gulf of Aqaba, or the Gulf of Eilat, is rich in coral and other marine biodiversity and is believed to be the habitat of one of the northernmost shallow water coral reefs in the world.

"We started simulating future conditions in the Red Sea to learn about how our corals here in the Gulf of Aqaba are doing with respect to elevated temperature, ocean acidification, and more local disturbances. We were amazed to find corals here are relatively resilient to climate change," said Fine, noting that no coral bleaching and mortality events have been found in the area.

"Corals usually bleach at one to two degrees above the summer thermal maxima. Here in the Gulf of Aqaba, they can withstand five and six degrees above that threshold."

Fine said the simulator system works by pumping water from the sea into the incubators, and then scientists change the conditions including temperature, ocean acidification and some other local stresses.

After being exposed for extended periods, sometimes months or over a year, the corals are taken to the lab for "thorough experiments" such as physiology, as well as photosynthesis and respiration rate checking.

Fine said all the corals are cultivated in a nursery underwater at sea. When scientists prepare corals for experiments, they will bring them to the simulator tanks.

"We never take the corals from the reef because we cannot afford to damage these amazing creatures," he stressed.

Xinhua